改进的多元线性回归模型及其应用

从EIV（Error-In-Variables）模型入手,对经典多元线性回归模型进行改进,并采用加权整体最小二乘估计准则（WTLS）对待估参数进行估计,最后针对新增观测信息的情况,导出其参数估值修正递推算法.通过建筑基坑支护桩水平位移监测实验表明,改进的模型较之经典模型能对水平位移变量进行更好的预测.参数修正递推算法的使用,避免了复杂的重复计算,计算效率明显提高.     

Spatio-temporal modelling of informal settlement development in Sancaktepe district, Istanbul, Turkey

In less developed countries, the recent high rates of urban expansion are often associated with the emergence of informal settlements that may exaggerate social and environmental problems and impede sustainable development. An enhanced understanding of informal development may, therefore, be a key for future success in its effective management. This paper explores the possibilities offered by progress in Geo-Information Science and spatial modelling to improve understanding of informal settlement development through comprehensive spatio-temporal analyses. First, it investigates spatial and temporal patterns of the growth of the informal settlements in Sancaktepe district of Istanbul between 1990 and 2005. Second, using a logistic regression model, an analysis of the driving forces of informal development and prediction of probable locations of new informal settlements are performed. A list of spatial factors that are correlated to informal development is compiled and used to build six logistic regression models for different time steps between 1990 and 2005. Population density, slope, and proportion of informal settlements in the neighbourhood were found to be the main predictors influencing the spatial development of informal settlements during the study period. The performance of the models is evaluated and validated to identify those which best explain the informal development in the study area. As a result, three models built for 1990-1995 and 1995-2000 were selected to generate probability maps of informal settlement development, showing the likelihood for each location to be informally developed in the future. These results can be used as a basis for the evaluation of the process of informal development in other parts of Istanbul, as well as in other cities and countries. At the same time, the technique may serve as a decision-making tool for urban planners and policy makers.     

基于高斯过程的精密卫星钟差加密

将高斯过程方法应用到精密卫星钟差加密中,通过选择合适的核函数,将5 min间隔的钟差数据插值到30 s间隔。将结果与IGS提供的30 s精密钟差数据和四阶多项式拟合插值方法得到的结果进行比较,结果表明,高斯过程方法具有较高的加密精度,适用于GPS所有在轨卫星的原子钟钟差的加密,达到厘米级精度。     

回归预测模型在隧道监测中的应用分析

比较了三种常用的回归曲线函数方程,计算了方程与数据之间的相关性,得到了能反映工程实际的最佳曲线。     

森林地上生物量的极化相干层析估计方法

基于微波的后向散射系数估计森林地上生物量(AGB)易受后向散射系数饱和的影响,而利用森林高度,根据生长方程估计AGB,却没有考虑和AGB密切相关的林分密度、树种组成、林层垂直分布等空间结构特征的作用,针对这些问题,提出一种基于极化相干层析(Polarization Coherence Tomography,PCT)技术的AGB估计方法。基于德国宇航局(DLR)机载SAR系统(ESAR)获取的特劳斯坦(Traunstein)试验区L-波段极化干涉SAR(PolInSAR)数据,通过对具有不同AGB水平的典型林分的相对反射率函数曲线的分析,定义了9个与AGB具有相关性的特征参数。然后基于20个林分的实测AGB数据,以林分尺度上这9个特征参数的平均值为自变量,以实测林分平均AGB为因变量,采用逐步回归分析法构建了AGB估测模型,并对该模型进行评价,对影响模型估计精度的因素进行分析,结果表明,由PCT提取的相对反射率函数特征参数对AGB很敏感,充分利用相对反射率函数信息可提高AGB估计精度。     

康熙《皇舆全览图》投影种类的统计分析

本文通过对《清廷三大实测全图集——康熙皇舆全览图》经纬线间距的仔细量测,并运用数理统计和回归分析的方法,从统计学上证实《皇舆全览图》的投影类型为桑逊投影。本文的研究显示,运用统计的方法判别古地图的投影方式可以解决因史料欠缺、测量误差以及图幅因年代久远变形而带来的不确定性等问题。     

平面直角坐标系间相似变换的外推精度估算

本文介绍了相似变换和一元线性回归分析原理,用一元线性回归模型对不同平面直角坐标系之间相似变换的外推精度进行了估算.用实例验证了估算的精度,在实际应用中具有很好的现实意义.     

Urban growth pattern modeling using logistic regression

Transformation of land use/land cover change occurs due to the numbers and activities of people.Urban growth mod-eling has attracted substantial attention because it helps to comprehend the mechanisms of land use change and thus helps relevant policies made.This paper tends to apply logistic regression to model urban growth in the Jiayu county of Hubei province,China.It is applied in a GIS environment to calculate variables and,then,in SPSS to discover the relationships between urban growth and the driving forces.The relative operating characteristic(ROC) shows the modeling accuracy with the curve 0.891 with standard er-ror 0.001.A probability map is generated finally to predict where urban growth will occur as a result of the computation.The result shows the model simulates urban growth well in the county scale.     

Ricker子波核最小二乘支持向量回归滤波方法的稳健性研究

除了信噪比、有效子波畸变等,稳健性(Robustness)也是度量滤波方法效果的一个重要的物理量,它刻画了滤波系统应对异常点值的能力.一般用影响函数作为评价稳健性的工具.支持向量机方法已较成功地应用于信号与图像的滤波中,尤其Ricker子波核方法更适于地震勘探信号处理.通过考察Ricker子波核最小二乘支持向量回归(L...     

Experimental study of the dynamic interaction between the foundation of the NEES/UCSD Shake Table and the surrounding soil: Reaction block response

An extensive experimental study of the dynamic interaction between the foundation block for the NEES/UCSD Large High Performance Outdoor Shake Table and the surrounding soil was conducted in 2003. The vibrations induced by the two NEES@UCLA large eccentric mass shakers were recorded at multiple stations within the reinforced concrete foundation block and on the surface of the surrounding soil up to distances of 270 m from the block. The present paper focuses on analysis of the data recorded within the reaction block including the average rigid body motion of the foundation and its dependence on frequency, and the deformation of the block for longitudinal (EW), transverse (NS), and torsional excitation. Comparison of the reaction block response during shaker induced vibrations with that for the much stronger actuator forces shows that linearity holds for the range of forces involved. Comparisons with analytical results for a simplified model of the foundation show good agreement between experimental and theoretical results.